There are low-power-consumption wireless communication techniques, such as Zig Bee and Bluetooth Low Energy, used to exchange low-capacity information every certain time. “Zig Bee” and “Bluetooth” are both registered trademarks.
In such a wireless communication technique, when a master apparatus and a slave apparatus establish a connection for communication, the slave apparatus just needs to make a request for connection to the master apparatus only when communication is required. Therefore, power saving can be realized in the slave apparatus.
On the other hand, the master apparatus does not know when the slave apparatus will make the connection request, and the master apparatus needs to always perform an operation of waiting for receipt of the connection request. Therefore, realization of power saving is difficult in the master apparatus. When the master apparatus is a battery-driven apparatus, such as a portable phone and a smartphone, the continuous use time is reduced if the power saving is not realized, and convenience is lost.
A technique for realizing the power saving of the master apparatus is disclosed in, for example, Patent Literature 1.
In the technique disclosed in Patent Literature 1, a master communication terminal that establishes communication links with slave communication terminals sets the same communication period for all communication links. The master communication terminal further sets communication start time and communication duration time for each communication link so that communication slots used in the communication links form a continuous range. The master communication terminal further negotiates with the slave communication terminals according to setting. The master communication terminal performs a power saving operation of the master communication terminal in a period of unused slots organized as one range, based on the setting.